As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
VERY ROUGH VIBRATION. PRONOUNCED FLUTTERING FELT LIKE COMING FROM TAIL DURING CLIMB FROM 18000. MAINT TEXT: CREW STATES VIBRATION FELT ALL FLT LEVELS AT HIGH SPEED SLOWING 30KNTS VIBRATION LESS NOTICEABLE. REPLACED RT ELEVATOR SERVO CONTROL 34CE2. FOLLOWING FLIGHTS REPORTED NO VIBRATION-SMOOTH CONTROL.